This invention relates in general to container closure devices and in particular to such devices which employ venting means as part of the pouring spout in order to allow air to enter the container without creating disruptions and pulsations in the exiting fluid flow.
The evolution of present-day container closure devices of a type similar to that disclosed by the present invention can be traced from as early as the mid 1940's by a review of the developments and improvements which are disclosed in the following chronologically arranged list of patents.
______________________________________ Patent No. Patentee Issue Date ______________________________________ 2,561,596 Rieke 7/24/51 2,565,699 Rieke 8/28/51 2,661,128 Rieke 12/01/53 2,895,654 Rieke 7/21/59 3,040,938 Smith 6/26/62 3,604,740 Summers 9/14/71 3,613,966 Summers 10/19/71 3,804,305 Rieke 4/16/74 ______________________________________
Rieke ('596) discloses a pouring spout which is nestable within a container and is extendable to a pouring orientation and contractable to a nested orientation. The spout is initially disposed in a closed arrangement by an integral portion which must be cut or slit in order to allow the contents to be poured from the container. The outer periphery of the pouring spout is secured to the container opening by means of a clamping ring of light metal which is readily deformed by a hand-operable crimping tool.
Rieke ('699) discloses a flexible, retractable dispensing spout normally nestable within a container and mounted in an opening therein. A junction portion signifies the point of union between the outer cap member, which forms the base of the extended spout, and the inner spout portion. The spout is sealed by a closure portion comprising a seal which is located immediately contiguous to the junction portion. The seal includes an integral pull member which extends upwardly from the seal and is located quite close to the inside surface of the spout portion. Removal of the seal is accomplished by the use of a tool, such as pliers, which have a suitable narrow-nose design in order to be able to grip the pull member without interfering with the inside surface of the spout portion.
Rieke ('128) is a continuation-in-part patent of patents Rieke ('596) and Rieke ('699) and further discloses a tamper- and seal-proof flexible pouring spout. A tamper-indicating seal is disposed over the end of the spout and may include a semi-severed, tear-out portion which must first be removed in order for the tamper-seal indicator to be removed. Alternatively, this tamper-indicating seal may be removed by a prying action. Disposed within the spout opening at the uppermost end is an integral plug which is joined to the inside periphery of the spout by means of an annular weakened junction which must be severed with a knife in order to open the spout.
Rieke ('654) discloses a bail handled closure cap of a character to be internally threaded for screw threading into closing position upon an externally threaded member, such as a container neck, spout or the like. The bail is connected with the cap through opposed and substantially diametrically extending bosses by means of suitable hinged arrangements.
Smith discloses a vented pour spout wherein a venting unit is rigidly secured to the inside surface of a flexible pour spout, of the type disclosed by the prior listed patents. This venting unit permits the entry of air into the container so as to enable a smooth, continuous flow of fluid from the container by way of the pour spout.
Summers ('740) discloses a container closure combination which is anchored into a container opening by means of a boss and circular anchor ring. The container is plastic and the boss includes an upwardly protruding lip which is sandwiched within an inverted U-shaped annular portion of the closure. The anchoring ring is disposed about the annular portion and when crimped together holds the members together. This arrangement precludes any separation or leakage at the closure, thereby overcoming typical cold flow characteristics of those plastics which are usually employed in such arrangements.
Summers ('966) discloses a nestable pouring spout with a wall-supporting cap of the style that includes an elongated skirt portion. This elongated skirt portion extends coaxially with the neck and body portions of the spout to a point near the intersection of these two portions. The space between the neck portion and body portion at this intersection location is large enough to permit easy removal of the cap and is small enough to permit the skirt portion to support the body portion and avoid stress cracking due to unrestrained movement of the body portion in response to internal container pressure.
Rieke ('305) discloses a container closure concept which includes a flanged overseal closure member having a central cap portion, an intermediate portion and a rim portion.
Although each component part of the overall closure cap assembly potentially represents an area for possible design improvement, the subject invention involves only the design and assembly of a venting unit for use with the type of container closure concept disclosed by these various prior art references and related closure structures. The vent design of the subject invention is an improvement over the Smith patent vent design in that fluid friction losses are accommodated by the rate of taper of the sides of the vent unit in order to assure a positive fluid pressure and prevent venting air from entering the pouring orifice. Further, the subject invention is an improvement for use with container contents which are extremely viscous in that the air entry ports are maintained with a very small clearance size which precludes the flow of viscous fluid into the air passageways.